That is not a solution, that is an abortion. You are wasting a lot of power being burned up for nothing. The real solution is to use the right battery to begin with. LiFePO4 aka LFP are the only lithium batteries that can be used as drop in replacements for Pb batteries. They use the exact same charge voltages as Pb. Not to mention a lot less expensive than your abortion. Sure hope no one takes your advice, it is dangerous and a waste of money and energy.